Experimental and Numerical Methods for Evaluating Fire Performance of Materials

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The long-term objective of this research program is to improve the knowledge of heat and mass transfer in materials subjected to high heat fluxes and temperatures during fires. Understanding heat and mass transfer under these conditions is critical, especially when evaluating fire safety. During this time period, progress will be made towards the overall research objective by focusing on two particular applications, where the literature, industry, regulators and end users indicate the need for improved models, and design and evaluation tools. Mattresses and Consumer Products. While the fire performance of building materials and systems (e.g., walls) and consumer products (e.g., mattresses) is evaluated for regulatory purposes using full-scale tests, such tests are very expensive and there are limited test facilities. Methods to predict full-scale fire behavior using small-scale tests would significantly reduce costs of fire testing for designers, manufacturers and regulators. However, reliable scaling methods do not currently exist. Our group has identified scaling methods with the potential to predict full-scale fire performance of polyurethane foam found in mattresses and other consumer products. These methods will be refined to better predict fire growth, and a flame spread model will be developed, along with recommended small scale test procedures for generating input data for the scaling models. Scaling methods for complete solid-core mattresses will be developed, taking into account the interaction of polyurethane foam with fabrics used as covers and fire barriers. Thermal Protective Clothing Our existing heat transfer models of single layer protective fabrics will be extended to predict the response of protective fabrics worn by firefighters, which include additional layers to manage moisture movement and increase thermal insulation. Of particular interest are relatively long term, primarily radiant exposures, such as during firefighting outside of a building. Moisture transport, which plays a major role in firefighter safety and comfort, will be added to the models, which will be validated using bench-scale fabric tests. As most standard tests are destructive, non-destructive tests will also be developed to evaluate the continuing performance of in-use clothing. Techniques that our group developed to predict changes in tensile strength using colour and infrared reflectance measurements will be refined, and additional tests will be developed to monitor and predict degradation of moisture transfer properties, thermal protection and other aspects of performance. Degradation due to laundering, abrasion and ultraviolet radiation will also be considered. Research will help better determine when clothing should be replaced, significantly improving safety of firefighters, and workers in the oil and gas, mining and other industries.